WRX 4 pot on LGT?

Yes if you swap with pads and rotors, but it is not an upgrade by no means.

How can you be so certain (despite the double negative, sorry)? I'd like to hear the opinion of someone who has done the swap (has anyone?). Perhaps it's already been discussed and I just missed it.

It might be a worthwhile trade to give up 1cm of diameter for opposed pistons. WRX brakes might not be as powerful, but better 'feel' and more consistent power and pad wear would be advantages.

Front:

Rotors; LGT 312mm (12.3 inches) vs WRX 292mm (11.5 inches)

Calipers; LGT 2-Piston Floating vs WRX 4-Piston Opposed

Rear:

Rotors; LGT and WRX 287mm (11.3 inches)

Calipers; LGT 1-Piston Floating vs WRX 2-Piston Opposed

Opinions...?

http://www.legacygt.com/forums/showthread.php?t=121057&highlight=brakes

some info on brakes and suspension there

Wow,threads from over a year ago were talking about how this subject was beaten to death already, hehe.

http://www.legacygt.com/forums/showthread.php?t=90267&highlight=4pot

http://www.legacygt.com/forums/showthread.php?t=84986&highlight=4pot

http://www.legacygt.com/forums/showthread.php?t=58835&highlight=4pot

http://www.legacygt.com/forums/showthread.php?t=119097&highlight=wrx+red+brakes

How can you be so certain (despite the double negative, sorry)? I'd like to hear the opinion of someone who has done the swap (has anyone?). Perhaps it's already been discussed and I just missed it.

It might be a worthwhile trade to give up 1cm of diameter for opposed pistons. WRX brakes might not be as powerful, but better 'feel' and more consistent power and pad wear would be advantages.

 

Front:

Rotors; LGT 312mm (12.3 inches) vs WRX 292mm (11.5 inches)

Calipers; LGT 2-Piston Floating vs WRX 4-Piston Opposed

 

Rear:

Rotors; LGT and WRX 287mm (11.3 inches)

Calipers; LGT 1-Piston Floating vs WRX 2-Piston Opposed

 

Opinions...?

You are actually sacrificing 20mm (2cm) of rotor diameter. Smaller rotor, smaller pads...go figure.

You are actually sacrificing 20mm (2cm) of rotor diameter. Smaller rotor, smaller pads...go figure.

There is also (most importantly) less piston area. More pistons does NOT equal better! The 4-pot WRX calipers may provide better pedal feel, but there is absolutely no way they will provide the same stopping power as the stock LGT setup. It is simply a matter of physics, so STiRA, hearing what someone thinks of the swap is a moot point. If you think it's cool, then by all means do it.

There is also (most importantly) less piston area. More pistons does NOT equal better! The 4-pot WRX calipers may provide better pedal feel, but there is absolutely no way they will provide the same stopping power as the stock LGT setup. It is simply a matter of physics, so STiRA, hearing what someone thinks of the swap is a moot point. If you think it's cool, then by all means do it.

Thanks for all the posts. I thought I might stir up some more discussion. Thanks for the correction on the diameter difference Waxiboy, I had just done the conversions so I must have been a bit confused.

I understand that smaller diameter rotors will offer less power due to a smaller braking surface (and leverage). In fact I mentioned that in my original post. However, braking is not just about power. Don't get me wrong, it's very important and it's probably still more important for us performance minded drivers than feel. I come from a motorcycle racing background and feel is very important too. I even chose the opposed piston brakes on my mountain bike over the floating caliper setup. From my experience (on my RS), floating calipers are susceptible to dirt impeding the caliper and causing brake problems. I suspect that the inconsistent shakes I'm experiencing are related to this problem. I've got to take everything off and have a look.

I was just hoping that someone had done the swap and could offer first hand feedback on the change in power and feel.

Plus I could run 16" wheels/tires in the winter and save some money!

Anyway, thanks again for the input on a topic that's now been resurrected and then beaten to death again.

Oh, wouldn't there be less flex in the caliper with opposed pistons and therefore more power...?

Flex wouldn't contribute to power loss, or gain. Just feel in the pedal.

Braking force is generated by the coefficient of friction of the brake pad, the piston area in the calipers, the leverage (distance the piston contacts the rotor from the center of the brake rotor) and the pressure behind the brake master cylinder.

If you are going for better feel, my guess is you'll achieve that cheaper and easier by going with a higher cF pad, like a carbotech XP8, by stainless steel brake lines and changing your brake fluid. Just the pads would make a huge difference, everything else much less of a difference.

I'm new to the legacy so I don't know if the brake master cylinder could benefit from a brace, but I really doubt it.

Not to mention the other big one, better tires. Those will stop you faster than anything else listed above.

*edit*

Oh and floating calipers are fine if you maintain them a little bit. If you are going to the track you'll need to get a high temperature grease for the floating pins, but likely they'll still burn the grease up if you are on DOT R tires.